Vehicle suspension and spring



A. s. Knofz A2,245,201

. vEHIcLE SUSPENSION AND SPRING Filed Dec. so, 1941 March 28, 1944.

5 Sheets-Sheet 1 March 28, 1944 I A. KRO-rz 2,345,201 y VEHICLESUSPENSION AND SPRING Filed Dec. 50, 1941 5 Sheets-'Sheet 2 mvg" March28,1944. A, s, KROTZ 2,345,201

VEHICLE SUSPENSIN AND SPRING Filed' Dec. 50 1941 5 Sheets-Sheet 3 I ILEgg/m 557@ Y v f5.

March 28,1944. `A, si, KROTZ 2,345,201

VEHICLE SUSPENSION AND SPRING Filed Dec. so, v1941 5 sheets-sheet 4 iii97 y 9o Y 89 95 9,2

wir@ 7 9 I 725 4 HMI-7 51E-D March 2s, 1944. A, s, KROTZ 2,345,201

VEHICLE SUSPENSION AND SPRING Filed Deo. :5o. 194i 5 sheets-sheet 5 /19y wl/4 y I? :ZZ

3 y j/L/' 525150.72*

#57M al '104 l /05 MIEL x Patented Mar. 28, 1944 UNITED STATES 'PATENTortica 'l ,i 2,345,201-

VEHICLE SUSPENSION AND SPRING Alvin S. Krotz, Ah'on, 0h10, assignor toThe B. F.

Goodrich Company, New York, N. Y., a corporation of New York 15 Claims.

This invention relates to vehicle suspensions and to springs, and isuseful especially in suspensions `for vehicles of the type having wheelconnections fixing the lateral spacing of the wheels, such for exampleas in the case of a through-axle. Features of the invention however areapplicable in other suspensions, for example, independent Wheelsuspensions.

The invention in many of its phases is applicable to rail-trucks as wellas to automotive trucks, busses, passenger cars, trailers and the likeand to the driving or non-driving ends and to the steering andnon-steering ends of such vehicles.

Thechief objects Iof the'present invention are to provide for springingAby torsional stress of rubber-like material supporting a. wheel throughan arcuately'movable structure, together with means for permittingstraight-line vertical movement of the Wheel despite the arcuatemovement of the connecting structure; to provide a resilientlyextensible'and contractible link arm for the purpose; to provide foraugmenting the action of the torsional spring to give a resultingvariable springing rate; and to provide for varying the springing rateto give the characteristics desired. y'

Further objects are to provide a spring assembly having a variablespring rate for resistance to relative vertical movement; to providemeans for resisting the reactions of driving torque and braking torque;to provide for a minimum of wearing parts; to provide durability andcompactness of structure, to provide an improved spring of generalapplicability, and to provide for vconvenience of manufacture andassembly.

` suspension constructed in accordance with and embodying the invention,

parts being broken away and sectioned.

Fig. 5 is a rear elevation of the suspension of Fig. el..`

Fig. 6 is a rear elevation of a modied drivingend suspension constructedin' accordance with and embodying the invention, parts being brokenaway.

Fig. 7 is a plan view of the construction of Fig. 6, parts being brokenaway and sectioned.

Fig. 8 is a section taken along the line 8 8 of Fig. 6.

Fig. 9 is a section on an enlarged scale taken along the line 9--9 ofFig. 8.

Fig. 10 is a plan view of a further modified form of driving-endsuspension.

Fig. 11 is a iront elevation of the modification ofvFig. 10.

Fig. 12 shows characteristic curves for the deilections of a wheelplotted against the loads on the wheel with the springing provided by avehicle suspension of the invention.

Fig. 13 is a plan view of a still further modified construction.

Fig. 14 is an elevation of the m'odication of Fig. 13.

The embodiment of Figs. 1, 2 and 3 of the drawings is illustrative ofthe suspension as applied to the steering end of a vehicle .of theheavy-duty type, such for example, as a truck or passenger bus, althoughpassenger cars and other types of vehicles are not excluded. Theconstruction shown here comprises a wheel, indicated generally at I 0'in Fig. 2, mounted on a spindle H and pivotally mounted at a king-pinI2 for movement to positions IIa and IIb shown by the dotted lines inFig. l to steer the vehicle. Control of movement of the spindle I Iabout the' king-pin I2 may be by means'of any suitable steering linkage,a member of which is shown at Fig. 2 is a. front elevation of thevehicle sus- 45 Fig. 3a is'a view like Fig. 3, but showing a por- 50tion of amodied construction. y

Fig. 4 is a plan viewof a driving-end suspension constructed inaccordanceA with and em- .bo'dying the invention.

tion and arrangement to spring the vehicle 'and to attain other ot therelated objects of the invention. 'Ihe resilient connection comprisesone or more telescopic link.; I8, I6, to be more fully describedhereinafter, which are pivotally connected at a frame member Il and theaxle I5. Two links, as shown, are desirable to resist the forces otbrake reaction tending to' rotate the axle by vertical forces at theconnection of the links with the axle.

The pivotal connections at the ends of the links I6, I9 are eachpreferably in the forni of a torsion spring or bushing I9 at the frameand in crossed relation with respect to the axle I5 and a pair ofpivotal connections I9, I9 at and extending crosswise of the axle I5.spring or bushing I8 may comprise a discontinuous sleeve member 29 heldwithin an outer housing 2|, an inner shaft member 22, preferably hollow,and a body '23 of rubber or other rubberlikematerial or other suitableresilient means rubber-like material of the telescoping connection.Relative movement between the frame and The torsion between the sleeve'29 and the shaft 22 for re-l sisting relative rotational and springingmovement between the sleeve 29 and the shaft 22 of the bushing I8. Therubber-like material of the spring or bushing I8 may be secured to thesleeve 29 and to the shaft 22 by means of a vulcanized bond,.or by anyother suitable fastening means, or in some cases, by the friction of thefit, without other attaching means.

` The telescopic links I6, I6 are xed to the housing 2I, as by weldingthe housings together, and the inner shaft 22 is secured, as forexample, by means of splines 24, 24, to projecting bracket members 25,25 at each end of the torsion spring I8 and fastened to the frame memberI1 as by means of bolts 29, 26 or other suitable attaching means.secured to exposed end portions of the shaft 22, and the housing 2| ofthe bushing I9 may be attached to a frame member. End-plates, one ofwhich is shown at 21, held by a long bolt 29 may be provided to maintainthe desired endwise location of the shaft 22 with respect tothe brackets25, 25.

, The pivotal connections I9, I9 may comprise outer sleeves I9a, I9a anda common inner shaft 29, the sleeves I9a, I9a and the shaft 29 beingseparated by bodies I9b, I9b of rubber or other rubber-like material toprovide resilient pivotal connections at the axle-end of the links I6,I5. The linksvI6, I6 are secured to the sleeves I9a. I9a `of themountings I9, I9. The inner shaft member 29 is secured to a bracketmember or ear 99 between the connections I9, I9 which member 99 isattached or constructed integral with the axlev I5 by means of aconnecting portion 9|. The sleeves I9a, I9a, to which the telescopiclinks I9, I9 are secured are capable of rotational movement relative tothe member 29 resisted by torsional and compressive stresses in therubberlike material I9b, I9b, thereby providing resilient 53211, 32a maybe provided to exclude foreign matter from the assembly, if desired.

The `springing is eifectedl by the combinedA action of the torsionspring and one or more springs in the connecting swinging andtelescoping link or arm structure which is effective at the same time topermit controlled relative vertical movement between the frame and theaxle oi the vehicle while restraining the extent of Alternatively, thelinks I6, I6 may be the axle isconilned to a substantially vertical pathunder deflections due to the irregularities of road-bed or track, asindicated by the positions of the pivotal connections at the axle ofamplitude and nature of springing movement under the control of thedesigner, as desired.

Details of construction of a suitable telescopic link are shown in theillustrative embodiment of Fig. 3 of the drawings, comprising an outerhousing 49, attached as by welding or brazing or other suitableattaching means to the housing 2I of the main torsion bushing I9, asindicated at 4I. An inner hollowu shaft member 42 is attached, as forexample by threaded portion 43 to projecting portion 44 of oneof themountings I 9.

A body 45 of rubber or other rubber-like material is vulcanized to,cemented to, or otherwise suitably adhered to an outer shell member 46`of the link, which member 46 is fixed .with respect to the housing 49and to an inner member 41 which is ilxed with respect to the inner shaft42. Spacing and bearing sleeve members 49 and 49 are disposed around theshaft 42 and between the inner member 41 and the ends of the shaft '42to prevent relative lengthwise movement bef portion 53 or bead on theinner surfaceof the outer housing 49 restrains wear-surface support--ing members 54 and 55 in the axial direction, and

member 55 is threaded to housing 49'in a manner such that surfaceportions 54a and 55a of members 54 and 55 are fixed with respect tohousing 49 and relative lengthwise movement between the housing 49 andthe shaft 42 is guided by sliding contact between the wear-surfaces 54a,55a `and the spacing andbearing members 49 and 49.

The rubber-like material in the bushing, in the mountings and in thetelescopic links is' preferably mounted under initial radial compressionto increase the effectiveness and durability ofthe assembly. lAlternatively, the housing 49 may be ilxed to the pivot I9, at the axleend of the connection and the inner shaft fixed at the bushing I9 at theframe end, as desired. The telescopic link construction permits relativevertical movement between the frame and the axle of the vehicle bylengthwise slidingmovement of the shaft 42 with respect to the housing49, which vertical movement is resisted by torsional stresses in therubber-like material of the bushing I9 and by shear stresses in therubberlike material 45 of the link, the extent of such deflections andthe stiffness of springing being controlled by the stiffness andeifective'shear such movement by shear stresses on the resilient area ofthe rubber-like ln'la'.terial 45. Despite the fact that the torsionspring alone ordinarily gives a springing rate (force required for alinear unit of deflection) that does not vary materially, a variablespringing rate is provided by the present construction, for, aswheeldeflection progresses there is a change in the amount of deectionper unit load. It is preferred in most applications to provide fordecreasing deflections per unit load as the deection increases. Anexample of the variable springing rate provided by the telescopic linksin combination with the torsion spring is illustrated by the curves inthe graph of Fig. 12, wherein curve A indicates the defiections underload for the torsion spring alone, curves B, B1 and B2 show thedeections under load for the telescopic link alone, and curve C showsthe deflections for the combined torsion spring and telescopic spring inthe operating condition of the latter represen'd by the curve B1.

The condition of the vehicle at zero static load, that is, empty ofpassengers in the case of a bus, is represented by the point in ythegraph. Changes in wheel deflection are plotted as abscissa, to the rightof 0 for increased loading and to the left oi 0 for decreased loadingfrom the static empty condition. The ordinates are changes in wheelloading, increasing above 0 and decreasing below 0 from the static emptycondition.

The curves B, B1 and B2 are representative of a family of curves showingspringing rates at the wheel resulting from variations in the initiallyadjusted condition of the spring -15 ofthe telescopic link, disregardingthe effect of the torsion spring i8. Where the arrangement or adjustmentis such that at the empty static, or neutral, condition of th vehiclethe shear spring 45 is under no stress in its axial direction, changesin loading will produce wheel deflection in accordance with curve B.Where the spring 45 in such neutral condition of the vehicle issubjected to shear stress by an axially shortened condition of thetelescopic link, the spring is first relieved of such stress as rwheeldeection progresses from the point 0 and after this spring passesthrough zero stress vit is stressed in the 'opposite axial direction.This action results in the curve B1 which crosses the axis of abscissaat points r, s where it passes through the condition of zero stress.Where the spring 45 is stressed by elongation of the telescopic link inthe neutral condition of the vehicle, the stress in this spring isincreased -in the same direction resulting in a curve B2 that is steeperthan the others.

The combined action of the straight shear spring 45 and the torsionspring I8 is represented by curve C which is the composite of curve A ofthe torsion spring and one of the family oi' curves of the straightshear spring, curve B1 being used by way of illustration.

The slope of the curves shows the rate of springing or the amount ofload per unit deflection, and the change in the springing rate asdeflection increases is indicated by the increasing slope of the curve Cfor large deections. Thus, for relatively light loads up to thefull-seated capacity of a bus, indicated approximately at the point C2,a relatively soft and Isteady rate of springing is provided as indicatedby the slope of the curve C between points C1 and Cz. At fullstandeeload C3, and for deilections beyond this point, the springing rateincreases rapidly to provide .greater resistance to deflectionsresulting from irregularities encountered in the road-bed and underheavy loads'.

Y joint of thelinks.

In the modified construction of Fig. 3a the threaded inner surface o'fthe' housing 40 and the matching threads in the outer surface of theshort sleeve member 46 provide means for varying the eective resistanceof the telescopic link and its adjusted position referred to bypermitting manual adjustment ,of the assembly to change the relativelongitudinal disposition of the assembly with respect to the housing.Any other suitable adjusting means may be provided, as desired, and thehousing may be fastened to the assemibly by any suitablemeans, as forexample by means of a set screw 56.

In the embodiment of Figs. 4 and 5 of the drawings the suspension isshown applied to the rearf end or driving-end of a heavy-duty vehicle ofthe type having dual rear wheels. Wheels 60, 60 are mounted on a spindle6l which extends through the Wheels 60, .60 and is supported by athrough-axle 62. The wheels are driven by means of a torque shaft 3 froman engine or other suitable source of power and through powertransmission means (not shown).

springing of the vehicle is provided for by a torsion bushing 64 mountedon a portion of the frame 65 of the vehicle by means of brackets 66, 66.The torsion bushing 64 is resiliently connected to the axle by means ofa pair of telescopic links 61, '61 as hereinbefore described andA fixedto mountings 68, 68 which are pivotally connected to wheel member 69througha xed member 1D.

The telescopic links 61, 61 permit relative vertical springing movementof the chassis and wheels lof the vehicle by torsional stresses in thetorsion bushing 64, but limit the extent of such movement by shearstresses in the rubber-like material in the links 61, 61 in series withthe slip By providing a pair of links, the tendency is resisted for theaxle to rotate under the forces of brake and drive reactions.

An embodiment of the vehicle suspension is shown as applied to a rear ordriving Wheel of a passenger car vehicle in Figs. 6 through 9 of thedrawings. The construction shown here comprises a pair of torsionbushings 85, at a wheel, as indicated in Fig. 8, and mounted on vathroughaxle housing 8| which iixes the lateral spacing of the rearWheels and encloses a torque shaft 82, which shaft transmits drivingforce from a diiferential, the housing of which is indicated at 83 inFig. 6, to the rear wheels of the vehicle, one of which wheels is shownat 84. The bushings 80, 80 may be spaced-apart at the axle housing 8iand each comprises a control shaftmember 80a, anv outer discontinuousvsleeve 80e, .and a body cf rubber or other rubber-like material 80hsecured thereto as by means of a vulcanized bond. The springs 80, 80 areattached to the axle housing 8| by means of a suitable mounting bracket85. The

torsion bushings 80, 80 may be adjusted rotationally in the housingbracket 85 as desired by means of anadjusting screw 85a mounted on abracket 85h in a manner to* engagea lug- 85c secured to the outerhousing 85d enclosing the bush- .ings 80,- 80.

4vehicle,lwhile resisting auch deections by a varother suitablefastening means.

iable stillness of the spring in the links 92, 92.`

A telescopic link 92 of the pair shown in Fig. 7

, comprises a housing 93, an inner shaft member 94 fixed to the housing99 of a mounting 99 and a body 95 of rubber or other rubber-likematerial between the housing 93 and the shaft 94 for resisting movementof the shaft 94 with respect to the housing 93 by shear stress in therubber-like material 99 while permitting vertical springing of thevehicle. The rubber-like material in the links 92, 92 is bonded, curedor otherwise suitably fastened to the shaft 94 and a sleeve 99 held atthe inner surface of the housing 93 by bolts 91, 91 or A sealing ring ofrubber-like material 99, for example, may be provided at the bushingendof a link 92 to exclude foreign matter from the assembly and may be heldas by flange member 99 on shaft 94. Alternatively, the housing 93, 93may be fixed to mounting 99,k 99 and inner shaft members 94, 94 may befixed to the housing 90, if desired. A lrubber bumper may be provided inframe member 91.

to prevent metal-to-metal contacts'under very severe deflections.

In the embodiment of Figs. l0 and l1 telescopicY tached to the innershaft |02 of the torsion bushing |03,'an outer housing member attachedto the pivotal connection |09 and an intervening body of rubber-likematerial ||2 secured as by means of a vulcanized bond or other suitableattaching means to annular sleeve members |3 and H4. The sleeves 3 and||4 are positioned by means of spacing members ||9 and ||9 which areflxed'with respect to the housing and spacing members ||1 and ||8 fixedwith respect to the shaft member 0. Relative sliding movement betweenthe contacting surfaces of the spacing members H9, ||9 and |l1, ||9 ispermitted under relative, vertical movement or deection between thewheels and the body of the vehicle and auch movement is resisted byshear stresses in the `rubber-like material 2; thereby providingcushioning of the vehicle and a variable rate of stinness ofspringingwith increasing stiffness for large deflections.1

A suitable bellows .||.9 is provided betweenthe torsion spring f 03 andthe telescopic link housing I to exclude foreign matter fromv thetelescopic link assembly.

' ally connected to the lower' end'of the king-pin,

as shown at |29. The shock-absorber arms l|23, |23 are pivoted at theirother ends to "a shock-absorber member,.indicated generally at |21, and19 mounted Ion a frame member |29. The long link arms |29, |29 arepivotally connected at their other ends to bracket members |29, |29secured to the frame member |29. An end of a single '5 ytelescopic link|30 incorporating a spring |30a. of

the type shownin Fig. 3 for example, is secured to a projecting bracketportion |3| of the kingypin |22 and at its other end to a torsionbushing |32 of the type hereinabove described. The bushing |32 extendslengthwise of the vehicle and is fastened at its ends to bracket members|33, |33 secured to the frame member |28.

To provide for elongation of the telescopic link under vertical movementofthe wheel |20 to stress the spring |30a of the link |30, the axis ofthe torsion bushing |32 is at a lesser distance from the king-pin |22than are the pivotal connections of the-arms |23, |23 and |25, |25 atthe frame so that vertical movement of the wheel compels change inylength of the link. Thus, a variable rate of springing of the vehicleis. provided for by the combined action of the spring |30a in the singletelescopic link |30 and the torsion bushing |32.

25 The arms- |25, |25 and |23, |23 may diverge from the king-pin |22 tospaced-apart positions at the frame member |29 in a manner to facilitateresisting the reactions of driving and breakingI torque.

Variations may be made without departing from the scope of the inventionas it is defined by the following claims.

I claim:

l. A vehicle suspension having a vheel struc- 'ture and an arm structureconnected to effect vertical springing by stress on a torsional springupon swinging movement of the arm, structure, in which said armstructure comprises a pair of relatively reciprocatory members and aspring interposed between said members to cushion relative reciprocatorymovement of said members upon swinging movement of the arm structure.

2. A vehicle suspension having a wheel structure and an arm structure`connected to effect vertical springing by stress on a torsional springupon swinging movement of the arm structure, in which said arm structurecomprises a pair of relatively reciprocatory members and a body ofresilient rubber-like material mounted between said members to cushionrelative reciprocatory movement of said members.

3. A vehicle suspension having a wheel structure and an arm structureconnected 'to' effect vertical springing by stress on a torsional springupon swinging movement of the arm structure, in which said arm structurecomprises a pair of relatively reciprocatory members and abody of.resilient rubber-like material mounted-between .said members to cushionrelative reciprocatory movement of said members by 'shear stress onsaid' body of resilient material.

-4. A vehicle suspension having a wheel structure and a connecting armstructure subject to swinging movement upon vertical movement of saidwheel structure, said suspension comprising a body of resilientrubber-like material mounted to resist1 swinging movement of said armstructure by torsional stressvof said body, and said arm structurecomprising telescopically associated members subject to telescopicmovement upon swinging movement of the arm structure and a, body ofresilient rubber-like material mounted between said members tov resistsuch telescopic movement thereof.

5. A vehicle suspension comprising laterally spaced-apart wheels, arigid interconnection determining the lateral spacing throughoutvertical movements of the wheels, arms subject t o arcuate swingingmovements by the vertical wheel movements, and torsion springs resistingsuch swinging movements of the arms, said arms each comprisingrelatively movable elements for permitting change of length of the armstructure and springing means interposed between said members to cushionthe relative movement thereof.

6. A vehicle suspension comprising laterally spaced-apart wheels, arigid interconnection determining the lateral spacing throughoutvertical movements of the wheels, arms subject to arcuate swingingmovements by vertical wheel movements, and bodies of rubber-likematerial in spaced-apart relation longitudinally of the vehicle, andmeans connecting said arms to said axle, said arms each comprisingtelescopically associated members and a body of resilient rubberlikematerial mounted to resist telescopic movement of said members by 'shearstress on said body.

8. A spring construction comprising a body of resilient rubber-likematerial for eilecting springing by torsional stress on said body, andan arm structure extending from said spring for imposing such torsionals'tress, said arm structure comprising a pair of members movable` withrelation to each other to change the eilective length of said armstructure and a body of rubber-like material mounted between saidmembers for resisting relative movement thereof.

9. A spring for a vehicle suspension comprising'l a body of resilientrubber-like material, an inner shaft element and an outer sleeve elementsecured to the rbody for imposing torsional stress on the body byrelative movement of said elements, an arm structure projectinglaterally from one of said elements and connected for swinging movementof the arm structure upon vertical movement of a vehicle wheel, said armstructure comprising an outer sleeve element,- an

the inner connecting member of said arm structure is mounted forreciprocatory movement in spaced-apart bearings in the sleeve elementand the body of resilient rubber-like material surrounds the innermember between said bearings and is secured to the inner memberv and tothe sleeve element.

11. A spring construction comprising a body of resilient rubber-likematerial, an inner shaft element and an outer sleeve element secured 'tothe body for imposing torsional stress on the body by relative movementof said elements, a second sleeve element secured to the first saidsleeve element and projecting laterally therefrom, an arm member mountedfor relative reciprocatory movement within the second said sleeveelement, and a body of resilient rubberlike material in the second saidsleeve element to resist said relative reciprocatory movement.

12. A spring construction as defined in claim 11 in which the 'body ofresilient material is mounted in said second sleeve element to resistthe reciprocatory movement by shear stress in the body. u

13. A spring construction comprising a body of resilient rubber-likematerial, an inner shaft element and an outer sleeve element secured toadditional sleeve elements to resist said reciprocatory movement.

14. A spring assembly comprising a structure mounted for both radial andcircumferential movement with respect to an axis, a bushing of.

rubber-like material at said axis having a laterally projecting armstructure connected to said structure for resisting movement of thestructure by torsional stress on said body of rubberlike material aboutsaid axis, said arm structure comprising telescopically associated partsand a body of resilient rubberlike material resisting telescopicmovement of said parts during swinging oi' said arm about said axisunder movement of said structure.

inner connecting member relatively movable axially, and a body ofresilient rubber-like material mounted between said sleeve element andmember to cushion such relative axial movement.

10. A spring as dened in claim 9 in which 15. A spring assemblycomprising supporting and supported structures and springing meansinterconnecting them, said means including a body of resilientrub'ber-like material for effect.- ing springingfmovementsby torsionalshear stress on said body, a second body of resilient rubberlikematerial for eecting rectilinear springing movement by straight shearstress on such second body, and means connecting said bodies forcompounding the springing action oi' said bodies.

ALVIN B. KRJOTZ.

